Vulnerability: Caught in an avalanche – then what are the odds?

Considerable Avalanche Danger - How much riskier is it?

Some calculations of risk for skiing at various levels of avalanche danger - from an ISSW 2009 paper.

Deep Slab Avalanche Research, Penticton, 4 May 2012

Mike Conlan talks about his research to improve the forecasting of deep slab avalanches..

Surface hoar by the aspect, Penticton, May 2012

Simon Horton talks about his research to predict the size of surface hoar hoar crystals that form on different aspects. He also presents his ideas for estimating the persistence of buried layers based on crystal size at burial and other factors.

Monitoring melt-freeze crusts in the snowpack

Ryan Buhler summarizes results from his last two winters of studying the changes in melt-freeze crusts after they are buried.

Extreme avalanches: How far will they go?

Alex Sinickas outlines the ideas and methods for her research into estimating extreme avalanche runout for land-use planning.

Driving a snowpack model with weather forecasts

Sascha Bellaire talks about simulating the snowpack with a computer model that inputs data from the GEM15 weather forecasts. By coupling the weather and snowpack models, the snowpack can be predicted anywhere. To see if or how well it works, watch the video.

A thermal peek into surface hoar growth

Surface hoar is quite particular. A number of different factors determine what aspects it grows on, and on what aspects it will grow bigger. This video shows a small area (~1 m on a side) with small rolls of snow that have very large surface hoar on only one side. A thermal image overlying the visual image gives us insight into why a small aspect difference makes a big difference in surface hoar crystals.

What causes temperature changes of the snow surface?

Thermal images of freshly exposed pit walls, about hourly, show the snow at and near the surface cooling rapidly when the sky cleared. When the sky became cloudy, the snow surface warmed by the greenhouse effect. These radiation effects are usually the dominant short term (24 h) effects except when rather strong wind warms or cools the surface. You can download the poster shown in the video from http://webapps2.ucalgary.ca/~asarc/files/ShallowSnowPoster_Shea_Jan2012.png.

Near crust faceting in a shallow snowpack

About twice per week at a shallow snowpack site in the Canadian Rockies during the winter of 2011, Cora Shea took thermal images of the pit wall and micro-photographs of the crystals in the crust and adjacent layers. It appears the less permeable crust contributes to faceting below the crust. You can download the poster shown in the video from http://webapps2.ucalgary.ca/~asarc/files/ShallowSnowPoster_Shea_Jan2012.png.

Changes in the temperature of a buried melt-freeze crust

During visits to a shallow snowpack in the Rockies during the winter of 2010-11, Cora Shea took thermal images of the freshly exposed pit wall, and micro-photographs of the crystals in and adjacent to the crust. Some days the crust was warmer than adjacent layers - suggesting net deposition of water vapour (faceting). Some days the crust was colder than adjacent layers. You can download the poster shown in the video from http://webapps2.ucalgary.ca/~asarc/files/ShallowSnowPoster_Shea_Jan2012.png.

Measuring the dynamic stress under skiers and snowmobiles

Scott Thumlert explains stress bulbs in the snowpack caused by skiers and snowmobiles moving over the snowpack, and summarizes the results from the the first winter of controlled measurements, including the strong effects of stiff surface layers as well as ski/sled penetration into the snowpack.

The Propagation Saw Test (PST)

Dave Gauthier explains why the PST was developed, shows two demonstrations of the propagation saw test, explains the usual interpretation of test results, and shows how it performed next to real avalanches and whumpfs over four winters.

Fracture Character in Compression Tests

This video summarizes some of Alec van Herwijnen's research on Fracture character. On skier-triggered slopes, two types of fractures - Sudden Planar and Sudden Collapse - were more common than other types of fractures.

Estimating extreme avalanche runout for two areas of BC

Katherine Johnston explains her MSc research on statistical estimation of extreme avalanches for the Columbia Mountains and for the Fernie Area.

SWarm - forecasting daytime snowpack warming over idealized terrain

SWarm is a free spreadsheet that estimates daytime warming 10 cm below the surface over idealized terrain. You can select the date, expected cloud cover, and days since snowfall to see how these factors can influence the daytime snowpack warming on slopes of various aspects and steepness.

GSWarm - understanding snowpack warming over real terrain

GSWarm is a website that displays the estimated snowpack warming for selected areas in western Canada such as Rogers Pass and Crowsnest Pass. You can select the date, expected cloud cover, and days since snowfall to see how these factors can influence the snowpack warming down 10 cm.

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The objectives, workings and limitations of GSWarm are described in Cora's 2010 ISSW paper

Spatial Variability

The snowpack is different everywhere. This is the theme behind the term 'spatial variability'. ASARC, in conjunction with previous work done at the SLF in Switzerland, is working to better understand what tests can help us understand stability despite the presence of spatial variability.

Recreational Snowpack Observations (RSO)

The RSO project combines observations from researchers across the three climate regimes (maritime, transitional, continental) to find out which observations matter the most for which regimes and avalanche types. These observations are designed to be fast and simple, for use on a day of recreational backcountry skiing or snowmobiling.

Measuring the stress under a falling skier

We are measuring the dynamic stress in the snowpack caused by skiers, snowmobiles, etc. This 11-second video shows a person falling directly above the stress sensors. Scott Thumlert is running the datalogger and stress sensors, which are hard to see in this video.

Measuring the dynamic stress under a moving snowmobile

As part of a research project on triggering of dry slab avalanches, MSc student Scott Thumlert has placed pressure sensors in the snowpack. A datalogger records the dynamic stress due to the snowmobile travelling over the pressure sensors.

The Swiss rutschblock, RB4

Sascha Bellaire rides a wild rutschblock. .

The Propagation Saw Test (PST)

Testing a surface hoar layer under a soft slab. Since the saw cut is less than half the column length and the fracture shoots to the end of the column, the test indicates fracture propagation is likely (where snowpack conditions are similar).

A Propagation Saw Test (PST) on the flats

Dave Gauthier demonstrates a propagatiion saw test on level ground. Chocolate powder has been blown onto the wall of the column to make the fracture (collapse) more visible.